I'm posting this so that it will show up in a search for folks having difficulty in installing mdac28.dll for a variuos applications using winetricks. I was stopped by issue #113 (Error 404 'Not Found' with winetricks installing mdac28/27/25) resulting from relocation of the setup file on the MS Downloads site, when I noticed that winetricks is a script. (Yes, well, I'm a newbie to linux!)
So I took a look at it and found that the following work-around works with a local copy of the mdac installer.
In a Linux terminal:
1. cp /usr/bin/winetricks to a safe place
2. cp /usr/bin/winetricks to an edit-able location
3. sudo chown [your user name]: [edit-able location]/winetricks
4. gedit [edit-able location]/winetricks
5. Search for load_mdac28
6. Comment out the first line of code in the subroutine beginning 'w_download mdac28 http://download.microsoft.com/download ....'
7. Save & exit gedit
8. sudo chown root:root [edit-able location]/winetricks
9. sudo cp [edit-able location]/winetricks /usr/bin/winetricks
10. mkdir /home/[your user name]/.cache/winetricks/mdac28
11. Go to MS Downloads site, search for MDAC_TYP.EXE and download it to /home/[your user name]/.cache/winetricks/mdac28/
12. winetricks mdac28
This installed mdac28 for me.
Finally, don't forget to restore your original winetricks from its safe place!
As always, use at your own risk.
Hope this helps someone :)